Written by Ana Elisa Sousa, Ph.D.
Summary of Bakermans-Kranenburg et al, 2019

As a new parent, it is normal to feel anxious, uncertain or insecure about what is to come. Many questions accompany parenthood (How will I keep my child safe, healthy and happy? How do I support my child’s development and don’t “mess it up”?), but becoming a parent also affects aspects of one's personal life, body and identity. While the impacts of motherhood are more often discussed - including the changes in sociocultural expectations, behaviours, hormones and the brain - such changes are less talked about when it comes to fathers.

At the same time, fathers spend much more time with their young children nowadays than they did a few decades ago. In the '70s, the average time a father used to spend in child care was between 11.8 minutes on weekdays and 25.3 min on weekends. In 2010, that average was estimated as 1.2 hours a day (both weekdays and weekends) - a three to six times fold increase.

Scientists have shown that a smoother transition to fatherhood during the first 1000 days of a child's life (the gestational period plus the 2 first years after birth) results in more and better quality involvement of fathers in the child's life in the following years, which in turn will have a positive impact in the child's development and the quality of the child-parent relationship. Below you will find a summary of the many factors influencing and influenced by fatherhood at a sociocultural, behavioural and biological level.

Society and environment

The accessibility and the duration of paternity leave will affect how much time a father can spend with their child in the first days, weeks and months of their life. Time spent with a newborn can, as you will see below, affect hormonal and neural changes in the father's body.
Work-related conditions and social expectations may push fathers to the role of secondary caregivers, in which they spend less time and have less responsibility in child care.
It is not uncommon for heterosexual couples that income differences between men and women make it more advantageous for the couple that the woman reduces her workload, while the man maintains or increases their own workload to compensate.
Mothers may be (consciously or unconsciously) reluctant to delegate caregiving responsibilities to their partners.
Breastfeeding tends to favour the mothers' proximity to the baby.

As a result, fathers tend to spend less than half as much time in one-to-one interaction with their children in early childhood.

Father's behaviour

Father’s behaviours during pregnancy can have a positive influence (e.g. quitting smoking) or a negative influence (e.g. violence towards partner) on their child's environment, positively or negatively influence the child's development before birth.
On the other side, expectant fathers’ behaviour can also be affected without their control. For instance, fathers can experience somatic pregnancy symptoms (also called Couvade syndrome).
- Somatic pregnancy symptoms affect up to 79% of fathers, depending on the criteria used by scientists.
- They include nausea, leg cramps, appetite and mood changes and weight gain.
- Though this syndrome may be linked to later parental responsiveness (i.e. being more sensitive to certain child behaviours), scientists have not yet found an association between having Couvade and being a better (or worse) father.
The creation of a bond between parent and child is an important milestone of early childhood. A few important aspects of the father-child bond to keep in mind:
- Fathers are as capable attachment figures as mothers
- Breastfeeding is not essential for the creation of a strong child-parent bond
- Though father's sensitivity to child's behaviours (e.g. crying) is usually lower than that of mothers, studies show that a similar proportion of children is securely attached to fathers and mothers
- Play, support of exploration and limit setting are three important father behaviours that favour the father-child bonding
- Depression (that can affect 4-10% of fathers-to-be) can negatively affect the quality of the father-child bond, the couple's relationship and it is linked to maternal depression.
  - These associations double the risk of a child's future challenging behaviours
  - It is important to identify signs of paternal depression and seek treatment as soon as possible

Hormones

Changes in hormonal levels during the transition to fatherhood both influence parental behaviour and are influenced by it.

Testosterone and Estradiol

In males, both hormones affect the regulation of sex drive, sperm production and mood.
Male's levels of testosterone and estradiol tend to decline during partner's pregnancy.
Research has shown that the greater the decline in testosterone level, the more fathers are involved in child care after birth.

Vasopressin

Vasopressin regulates blood water level and is also involved in human attachment, relationships and control of aggressivity.
Vasopressin levels seem to influence father's response to a baby crying and overall be linked to paying more attention to the baby's distress and stimulating father-child interactions

Oxytocin

Oxytocin is important in the regulation of human behaviour and social interactions.
Its levels increase over the first 6 months of fatherhood.
That increase is associated with fathers playing more with their children.

Cortisol

It’s the "stress" hormone: its level rises when we are under stressful situations. Cortisol helps to control blood sugar levels and blood pressure, regulate metabolism, reduce inflammation and support memory processes.
Low base-levels of cortisol are linked to more sensitive parenting
Cortisol levels increase in the father when listening to child cry and decrease when they hold their newborn or interact with their toddler
High cortisol reactivity (e.g. rising when baby cries, lowering when holding baby) seems linked to a better quality of fathering behaviour
Cortisol and testosterone levels interact with each other to regulate parental behaviour. When testosterone levels are high, higher cortisol levels are associated with poorer parenting.

Brain changes

Father's brain volume changes after childbirth.

This change only happens in specific areas. For example, animal studies have shown volume increases in regions specialized in detecting infant cues (e.g. what kind of crying is that?) and those that regulate parenting behaviours (e.g. what do I do when I hear this crying?)

Brain activation (how the brain respond in a situation) also changes with fatherhood
- The brain connections between the amygdala (emotional processing area) and superior temporal sulcus (involved in social understanding) become stronger with child care
- Both mothers and fathers activate more the sensorimotor network (responsible for turning an environmental cue into action) when listening to a child cry, compared to nonparents, an indicator that they may be more sensitive to act to that sound.
- After the birth of a child, males seem to become more empathetic to other children in distress, as they tend to show a similar brain activation (sensorimotor areas) when imagining their own child and other children in distress only after they have become fathers.

Key points

Fatherhood affects and is also affected by different aspects of one’s life
Some aspects in one’s life during that period facilitate the transition to fatherhood, while others may result in challenges to bond, engage in child care and support a healthy child development
Mothers and fathers transition to parenthood in different ways
Being aware of the factors that can affect your transition to fatherhood can better support the choices you make as a father

Meet Ana

Ana Elisa Sousa obtained her doctoral degree in neuroscience at the McGill University in Montreal, where she studied cognitive remediation in severe mental illness. Before moving to Canada, Anaobtained a bachelor’s degree in psychology at the Federal University of Bahia, located in the sunny city of Salvador, Brazil. She has a special interest in child development, mental health, and effective science communication with non-scientists.